//
// X509Certificate.h
//
// Library: Crypto
// Package: Certificate
// Module:  X509Certificate
//
// Definition of the X509Certificate class.
//
// Copyright (c) 2006-2009, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Crypto_X509Certificate_INCLUDED
#define Crypto_X509Certificate_INCLUDED


#include <istream>
#include <set>
#include <vector>
#include <openssl/ssl.h>
#include "Poco/Crypto/Crypto.h"
#include "Poco/Crypto/OpenSSLInitializer.h"
#include "Poco/DateTime.h"
#include "Poco/SharedPtr.h"


namespace Poco
{
namespace Crypto
{


    class Crypto_API X509Certificate
    /// This class represents a X509 Certificate.
    {
    public:
        typedef std::vector<X509Certificate> List;

        enum NID
        /// Name identifier for extracting information from
        /// a certificate subject's or issuer's distinguished name.
        {
            NID_COMMON_NAME = 13,
            NID_COUNTRY = 14,
            NID_LOCALITY_NAME = 15,
            NID_STATE_OR_PROVINCE = 16,
            NID_ORGANIZATION_NAME = 17,
            NID_ORGANIZATION_UNIT_NAME = 18,
            NID_PKCS9_EMAIL_ADDRESS = 48,
            NID_SERIAL_NUMBER = 105
        };

        explicit X509Certificate(std::istream & istr);
        /// Creates the X509Certificate object by reading
        /// a certificate in PEM format from a stream.

        explicit X509Certificate(const std::string & path);
        /// Creates the X509Certificate object by reading
        /// a certificate in PEM format from a file.

        explicit X509Certificate(X509 * pCert);
        /// Creates the X509Certificate from an existing
        /// OpenSSL certificate. Ownership is taken of
        /// the certificate.

        X509Certificate(X509 * pCert, bool shared);
        /// Creates the X509Certificate from an existing
        /// OpenSSL certificate. Ownership is taken of
        /// the certificate. If shared is true, the
        /// certificate's reference count is incremented.

        X509Certificate(const X509Certificate & cert);
        /// Creates the certificate by copying another one.

        X509Certificate & operator=(const X509Certificate & cert);
        /// Assigns a certificate.

        void swap(X509Certificate & cert);
        /// Exchanges the certificate with another one.

        ~X509Certificate();
        /// Destroys the X509Certificate.

        long version() const;
        /// Returns the version of the certificate.

        const std::string & serialNumber() const;
        /// Returns the certificate serial number as a
        /// string in decimal encoding.

        const std::string & issuerName() const;
        /// Returns the certificate issuer's distinguished name.

        std::string issuerName(NID nid) const;
        /// Extracts the information specified by the given
        /// NID (name identifier) from the certificate issuer's
        /// distinguished name.

        const std::string & subjectName() const;
        /// Returns the certificate subject's distinguished name.

        std::string subjectName(NID nid) const;
        /// Extracts the information specified by the given
        /// NID (name identifier) from the certificate subject's
        /// distinguished name.

        std::string commonName() const;
        /// Returns the common name stored in the certificate
        /// subject's distinguished name.

        void extractNames(std::string & commonName, std::set<std::string> & domainNames) const;
        /// Extracts the common name and the alias domain names from the
        /// certificate.

        Poco::DateTime validFrom() const;
        /// Returns the date and time the certificate is valid from.

        Poco::DateTime expiresOn() const;
        /// Returns the date and time the certificate expires.

        void save(std::ostream & stream) const;
        /// Writes the certificate to the given stream.
        /// The certificate is written in PEM format.

        void save(const std::string & path) const;
        /// Writes the certificate to the file given by path.
        /// The certificate is written in PEM format.

        bool issuedBy(const X509Certificate & issuerCertificate) const;
        /// Checks whether the certificate has been issued by
        /// the issuer given by issuerCertificate. This can be
        /// used to validate a certificate chain.
        ///
        /// Verifies if the certificate has been signed with the
        /// issuer's private key, using the public key from the issuer
        /// certificate.
        ///
        /// Returns true if verification against the issuer certificate
        /// was successful, false otherwise.

        bool equals(const X509Certificate & otherCertificate) const;
        /// Checks whether the certificate is equal to
        /// the other certificate, by comparing the hashes
        /// of both certificates.
        ///
        /// Returns true if both certificates are identical,
        /// otherwise false.

        const X509 * certificate() const;
        /// Returns the underlying OpenSSL certificate.

        X509 * dup() const;
        /// Duplicates and returns the underlying OpenSSL certificate. Note that
        /// the caller assumes responsibility for the lifecycle of the created
        /// certificate.

        std::string signatureAlgorithm() const;
        /// Returns the certificate signature algorithm long name.

        void print(std::ostream & out) const;
        /// Prints the certificate information to ostream.

        static List readPEM(const std::string & pemFileName);
        /// Reads and returns a list of certificates from
        /// the specified PEM file.

        static void writePEM(const std::string & pemFileName, const List & list);
        /// Writes the list of certificates to the specified PEM file.

    protected:
        void load(std::istream & stream);
        /// Loads the certificate from the given stream. The
        /// certificate must be in PEM format.

        void load(const std::string & path);
        /// Loads the certificate from the given file. The
        /// certificate must be in PEM format.

        void init();
        /// Extracts issuer and subject name from the certificate.

    private:
        enum
        {
            NAME_BUFFER_SIZE = 256
        };

        std::string _issuerName;
        std::string _subjectName;
        std::string _serialNumber;
        X509 * _pCert;
        OpenSSLInitializer _openSSLInitializer;
    };


    //
    // inlines
    //


    inline long X509Certificate::version() const
    {
        // This is defined by standards (X.509 et al) to be
        // one less than the certificate version.
        // So, eg. a version 3 certificate will return 2.
        return X509_get_version(_pCert) + 1;
    }


    inline const std::string & X509Certificate::serialNumber() const
    {
        return _serialNumber;
    }


    inline const std::string & X509Certificate::issuerName() const
    {
        return _issuerName;
    }


    inline const std::string & X509Certificate::subjectName() const
    {
        return _subjectName;
    }


    inline const X509 * X509Certificate::certificate() const
    {
        return _pCert;
    }


    inline X509 * X509Certificate::dup() const
    {
        return X509_dup(_pCert);
    }


}
} // namespace Poco::Crypto


#endif // Crypto_X509Certificate_INCLUDED
